Arc-welding electrode



posited metal contains HARRY B. PENNINGTON, OI CHICAGO,

WAUKEE, WISCONSIN, ASSIGNORS TO C. H. HOLLUP CORPORATION,

. the desired Patent ed Dec. 18, 1928;

UNITED STATES.

PATENT OFFICE.

OI ILLINOIS.

No Drawing.

' This .invention relates to improvements, in electrodes of the type used at present in elec tric arc welding practice. In welding pieces of metal, or in building up'a piece by depositin thereon the molten metal of an electrode, it,1s often desirable that the deposited metal have a certain'percentage of carbon therein. It is known that a weld made by, or metal de- -posited by-an electrode having a certaln carboncontent will not have the same percentage of carbon as the electrode, due to dissipation of the same during the welding operation. Oftentimes it is found that the denot more than fifty per cent of the carbon present therein before fusing. It is not entirely practical to provide the electrode itself with such a quantity of carbon that the deposited metal willfhave rcentage after cooling since difficulties arise in drawing the wire or rods of which the electrodes are formed where the metal has a high carbon content, especially where the wires are of relatively small diameter.

The principal object of our invention therefore tioned by providing electrodes which will assure that the resultingweld or deposit .of metal will have the desired percentage of carbon therein. In carrying out our invention, we may use electrodes which have 11 carbon content much less than thatxlesired for rod having a relatively the deposited metal, the difierence being supplied by a coating applied to the electrode before the welding operation.

Under present day practice, a mild steel small percentage of carbon will make a weld of not morethan one-tenth of one percent carbon content. .Such a mild steel rod after having been coated in accordance with our invention will make a weld which may have a carbon content ofover one percent, if desired. The quantity of carbon in the weld may be varied by varying the coating applied to the electrode,

We are aware that it has been 'proposed heretofore to increase the carbon content of the weld metal by coating the electrode with a form of carbon and binder, but commercial ABC-WELDING ELECTRODE.

is to overcome the difliculties men- ILLINOIS, AND CHARLES H. HOLLUP, OF MIL- A CORPORATION success has not been attained due to the fact that the applied carbon is lost by xidization,

or otherwise, during the welding operation which. results in the weld metalhaving a variable or unreliable percentage of carbon.

-. The ingredients of which our coating for the electrode is composed may consist of a com ound of an alkaline earth metal, prefera .y ari'um car ona e, w 16 is suitably mixed with approximately an equal quantity by volume of powdered carbon preferably in coke form, said mixture Being made into a paste by the addition of a diluted solution ofsodium silicate. with this mixture either by applying the same thereto by hand, as with a. brush, or by dipping the electrocles into the mixture. Va-

rious proportions of the ingredients may, of

course, be used when found desirable.

It, will be found that the metal deposited by our coated electrode will have a uniform distribution of carbon throughout its mass, the quantity of which can be varied as desired by; varying. the quantity of'the coating app 'ed to the electrode.

By way of example, it might be stated that analysis of the weld metal where a one-eighth inch electrode was used having a carbon content of one-tenth of one percent and a coating of our composition one-thirty-second of an inch in thickness, showed a. carbon content of the weld metal of one and 66/100 percent.

EXAMINER The electrodes are coated We have also found that an increase in the quantity of carbon given to the weld metal will resultif the electrode forms the anode or positive terminal of the arc.

This is the reverse of the general practice in electric welding at the present time, par- Instead of carbon in coke form, we have com ounds, starch M w g u-s-w What we claim is:

A coatin for welding rods comprising a mixture ofiarium carbonate, and powdered carbon in substantially equal volumes and a diluted solution of sodium silicate.

In testimony whereof, we have subscribed 15 our names.

HARRY R. PENNINGTON. CHARLES H. HOLLUP. 

